The purpose of this project is to objectively evaluate the efficacy and clinical toxicity of drugs given to outpatients to alleviate apprehension associated with dental procedures. Measures of efficacy assessed include relief of anxiety, analgesia, amnesia and patient cooperation. Measures of clinical toxicity include respiratory and cardiovascular depression, psychomotor impairment and central nervous system depression. Previous work indicates that the combination of diazepam, fentanyl and methohexital causes a significant decrease in respiration rate and oxygen saturation while the combination of diazepam and methohexital does not depress respiration. A second study suggests that these two combinations are causing a transient decrease in stroke volume which may account, in part, for the subsequent reflex tachycardia seen. Recent work has been aimed at developing more sensitive and reliable scales for assessing the subjective effects of anti-anxiety agents. These newer scales are being employed, in conjunction with physiological and psychomotor assessment procedures, to evaluate traditional and novel anti-anxiety agents and combinations.